This invention relates generally to the field of magnetic disk devices. Currently, the trend in magnetic disk devices is to store more data in less space. Typically, high density magnetic recording media devices are obtained by reducing the flying height of a read/write head with respect to the media surface.
Contact start stop (CSS) recording is one particular technique that uses a low flying read/write head to maximize density on a media. In CSS recording, the read/write head contacts the disk surface during starting and stopping. In between starting and stopping, the read/write head flies over the disk and is suspended in air by a slider facing the surface of the media. The high speed motion of the disk causes air to be carried along with it, and the contour of the slider gives rise to an aerodynamic flotation cushion providing a constant, controlled separation between the disk and the read/write head.
A major problem associated with CSS recording media is that "stiction" develops at the interface of the read/write head and the surface of the magnetic disk. Stiction is the combination of friction and "stickiness" at the magnetic media surface that causes the read/write head to adhere to the surface, making it harder for the head to initiate movement therefrom. Typically, stiction occurs when the magnetic media surface is too smooth. To overcome stiction, a large force needs to be applied to the read/write head to initiate movement from the surface. Stiction can become high enough to cause damage to the head, the media, and the head suspension, which cause the head to crash into the magnetic media.
Another problem associated with the CSS recording media is that its surface is very smooth. Although a smooth media surface permits the read/write head to fly closer to the media surface, it is not very durable because the amount of lubricant that can be retained is very little.
One way of preventing stiction and increasing the durability of the media surface is to mechanically texture or rough the disk with lubricated peaks and valleys. Thus, the read/write head can rest on the peaks during starting and stopping, thereby reducing the contact area between the head and media. By resting on the peaks, the amount of force necessary to initiate movement of the read/write head is considerably less.
The mechanically textured peaks and valleys are formed by pressing an abrasive (i.e., emery tape) against a rotating media. While this process has been used to prevent stiction, it does have serious drawbacks. One major problem is that this process cannot be controlled. Thus, there is a tendency for the mechanically textured peaks and valleys to be nonuniformly distributed and to have poor texture quality in terms of depth, width, and height. Another drawback is that nonuniform peaks are highly stressed and brittle. This increases the probability that a low flying read/write head will interact or collide with the peaks. The interaction causes wear on the media and debris to deposit on the read/write head. Debris disturbs the air flow and eventually, the read/write head becomes unstable and loses its ability to lift due to debris pile-up and crashes onto the media surface. Another problem is that the mechanically textured process, when applied to a glass substrate causes microcracks to occur at the surface.
Consequently, there is a need for an improved process for texturing a rigid magnetic thin film media to provide lower wear, reduced stiction, and debris generation for very low flying read/write heads.